Method and apparatus for creating a sub-atmospheric pressure inside closed containers

ABSTRACT

Method and apparatus for creating a sub-atmospheric pressure inside closed containers in which said containers are introduced into a duct full of liquid which moves from an inlet to an outlet of said duct, said liquid carrying the containers in the stream, part of said liquid being at atmospheric pressure, one section of said duct being a barometric leg, being placed higher than the part of the liquid at atmospheric pressure, the level difference being such that the containers are permanently enlarged.

United States Patent Hauser et al.

METHOD AND APPARATUS FOR CREATING A SUB-ATMOSPHERIC PRESSURE INSIDE CLOSED CONTAINERS Inventors: Ivo I-Iauser, Vevey; Werner Hiltbrunner, Berne, both of Switzerland Societe dAssistance Technique pour Produits Nestl S.A., Lausanne, Switzerland Filed: Mar. 7, 1974 Appl. No.: 449,149

Related US. Application Data Continuation-in-part of Ser. No. 240,956, April 4, 1972, abandoned.

Assignee:

Foreign Application Priority Data Apr. 14, 1971 Germany 2118137 US. Cl 113/1 G; 113/120 M; 29/421; 72/54; 426/404 Int. Cl B21d 51/26 Field of Search 113/1 R, l G, 120 M; 72/54; 29/421; 99/467, 471, 472; 264/313; 425/388; 426/131, 395, 404; 53/22 References Cited UNITED STATES PATENTS 11/1915 Shaffer 426/395 O l-I i 1145] May 27, 1975 3,789,785 2/1974 Petit a a1. 113/1 0 FOREIGN PATENTS OR APPLlCATlONS 758,450 1/1971 Belgium 113/120 M 1,287,503 3/1972 United Kingdom 113/120 M OTHER PUBLICATIONS Sailing Directions and General Information The Panama Canal, published April 1915; call No. VK 970.P2A5; pages 7-10.

Primary Examiner-Richard J'. Herbst Attorney, Agent, or FirmBlum, Moscovitz, Friedman & Kaplan 571 I ABSTRACT Method and apparatus for creating a sub-atmospheric pressure inside closed containers in which said containers are introduced into a duct full of liquid which moves from an inlet to an outlet of said duct, said liquid carrying the containers in the stream, part of said liquid being at atmospheric pressure, one section of said duct being a barometric leg, being placed higher than the part of the liquid at atmospheric pressure, the level difference being such that the containers are permanently enlarged.

8 Claims, 2 Drawing Figures SHEET PATENTEU W2 71975 H; M I A v. H 2 4/ 0 9 1 "is .lllllll- 4 P a: 1 5 m I ml.r\no

PATENTED 3,885,510

SHEET 2 METHOD AND APPARATUS FOR CREATING A SUB-ATMOSPHERIC PRESSURE INSIDE CLOSED CONTAINERS CROSS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of our copending application Ser. No. 240,956 filed Apr. 4, 1972, now abandoned.

BACKGROUND OF THE INVENTION This invention is concerned with a method and apparatus for creating a sub-atmospheric pressure inside closed containers, filled and/or sealed at atmospheric pressure, in order that the contents do not squirt out when opening the containers.

A method of this kind is described in Belgian Pat. No. 758,450 granted Jan. 15, 1971 and corresponding to British Pat. No. 1,287,503. Briefly, a closed container filled and/or sealed at atmospheric pressure is placed in a chamber which is evacuated. Due to the pressure difference between the inside and the outside of the container, the container wall is deformed and the volume of the container increases. If the deformation of the wall exceeds the limit of elasticity of the wall material, the deformation remains permanently and the container is still enlarged even after it is placed again in a surrounding atmospheric pressure. The increase in volume of the closed container creates inside a sub atmospheric pressure.

The method described in this patent, however, is a noncontinuous operation.

The method according to the invention provides a continuous mode of operation for creating a subatmospheric pressure inside closed containers. The invention relates also to an apparatus for carrying out this method.

According to the method of the invention for creating a sub-atmospheric pressure inside closed containers filled and/or sealed at atmospheric pressure, said containers are introduced into a duct full of liquid which moves from an inlet to an outlet of said duct, said liquid carrying the containers in the stream, part of said liquid being at atmospheric pressure, one section of said duct being a barometric leg, being placed higher than the part of the liquid at atmospheric pressure, the level difference between said section and said part of the liquid at atmospheric pressure being such that the containers are permanently enlarged.

The apparatus according to the invention for creating a sub-atmospheric pressure inside closed containers filled and/or sealed at atmospheric pressure comprises a duct full ofliquid with an inlet and an outlet, a supply ofliquid, said liquid moving from the inlet to the outlet, part of said liquid in the duct being at atmospheric pressure, a section of said duct being a barometric leg, being placed higher than the part of the liquid at atmospheric pressure.

DESCRIPTION OF A PREFERRED EMBODIMENT The following description of a preferred embodiment refers to the attached drawing in which FIG. 1 is a diagram of an apparatus according to the invention;

FIG. 2 is another diagram of the same apparatus as in FIG. 1.

A duct, generally designated by 1, is full of a liquid, preferably tap water, moving in the direction of the arrows from the inlet 17 to the: outlet 12. This water is supplied from buffer supply reservoir 6 which itself is fed by the water mains 5. In another embodiment, the

duct 1 is fed directly by the water mains. The water keeps flowing from the inlet to the outlet by the fact that the outlet 12 of the terminal section 11 is lower than the next lowest section 4 of the duct. This gives a syphon effect, the height of the water column between the section 4 and the outlet 12 being higher than the height of the water column corresponding to the hydro dynamic friction losses of the water in the duct.

There is a buffer reservoir 2 in the circuit which communicates with the section 1' of the duct 1 by the hole 3, at the bottom of the barometric leg which will be defined later. The level S of the water in this reservoir is adjustable by means of the three-way valve 15. By this three-way valve, the reservoir 2 is connected to the water mains, or to an outlet, or the outlet is closed. According to the position of the three-way valve, the level S of the reservoir 2 rises, sinks or remains stable. Above the level S, the reservoir is in communication with the surrounding atmosphere by the pipe 14. By a similar pipe 16, the section 4 of the duct 1 is in communication with the surrounding air also, it being understood that the water in the pipe 16 rises approximately at the same level S as in the reservoir 2.

The whole section 7 of the duct 1 is above the water level S which is itself at atmospheric pressure. It is therefore apparent that this whole section is a barometric leg and that the water in this section is at subatmospheric pressure, the lowest pressure being at the highest level H of section 9. The negative pressure at H (relatively to the atmosphere) is a function of the difference in height A h between the level S of the reservoir 2 at atmospheric pressure and the level II. It should be noted that the level S is adjustable by means of the three-way valve 15 and therefore the negative pressure at H may be adjusted.

In a preferred embodiment, the section 9 is provided with a pump 13 which draws the air occluded in the liquid and thus serves as an air eliminator.

Preferably, the section 8 is wound in order to lengthen the circuit and in .10 are provided heating means. The role of these two sections will be explained later.

The operation is as follows:

The closed containers which were filled and sealed at atmospheric pressure and in which a sub-atmospheric pressure shall be created, are introduced into the circuit by the inlet 17. Due to the angle of this inlet with the duct 1 and the movement of the liquid, no lock is necessary.

The containers are now carried away in the duct in the direction of the arrows by the stream of water. They cannot go out of the hole 3,, the latter being smaller than the containers.

The lengthened, wound section 8 at sub-atmospheric pressure is intended to check whether the containers are really closed and air-tight. By subjecting them to a subatmospheric pressure during a prolonged time, the leaky containers will be emptied of the air enclosed in them. The section 8 being long enough, the air will escape even if the leak is microscopic. The material contained may escape as well into the liquid of the duct as the case may be. In this way, an equilibrium between the inside and outside pressure of the container will be reached and the container will not be deformed as is explained further. This lack of deformation is noticeable after the leaky containers come out of the apparatus and thus identified, they may be discarded.

Properly sealed containers are subjected in the whole section 7 to a pressure difference between the inside, which is at atmospheric pressure since they were filled and sealed, and the surrounding liquid which is at subatmospheric pressure. They are thus deformed and their volume is increased. By properly adjusting the level S and choosing an appropriate negative pressure in section 9, the deformation will be such that the limit of elasticity of the material of the container wall is exceeded. In this way the deformation becomes permanent and the increase in volume remains, even after the containers come out of the apparatus at 12 and return to the surrounding atmospheric pressure.

The pressure difference between the inside and outside of the containers may be increased by way of the heating means 10, which heat the liquid in the duct and hence the contents of the containers. This increases the pressure difference by dilation of the contents.

Finally, the containers come out of the apparatus at 12.

While certain preferred forms and methods of this invention have been shown and described, the invention is easily capable of variation and modification from the forms shown so that its scope should be limited only by the scope of the claims appended hereto.

We claim:

1. Apparatus for creating a sub-atmospheric pressure inside closed containers filled and/or sealed at atmospheric pressure, comprising a duct full of liquid with an inlet and an outlet. a supply of liquid, said liquid moving from the inlet to the outlet, part of said liquid in the duct being at atmospheric pressure, a section of said duct being a barometric leg, being placed higher than the part of the liquid at atmospheric pressure.

2. Apparatus according to claim 1, in which the supply of liquid comprises a buffer supply reservoir.

3. Apparatus according to claim 1, in which a buffer reservoir is connected to the duct at the bottom of the barometric leg.

4. Apparatus according to claim 3, in which the level of said reservoir is adjustable.

5. Apparatus according to claim 1, in which the duct comprises a lengthened, wound section.

6. Apparatus according to claim 1, in which the duct is provided with heating means.

7. Apparatus according to claim 1, in which the duct is provided with an air eliminator.

8. Method for creating a sub-atmospheric pressure inside closed containers, filled and/or sealed at atmospheric pressure, in which said containers are introduced into a duct full of liquid which moves from an inlet to an outlet of said duct, said liquid carrying the containers in the stream, part of said liquid being at atmospheric pressure, one section of said duct being a barometric leg, being placed higher than the part ofthe liquid at atmospheric pressure, the level difference between said section and said part of the liquid at atmospheric pressure being such that the containers are per manently enlarged. 

1. Apparatus for creating a sub-atmospheric pressure inside closed containers filled and/or sealed at atmospheric pressure, comprising a duct full of liquid with an inlet and an outlet, a supply of liquid, said liquid moving from the inlet to the outlet, part of said liquid in the duct being at atmospheric pressure, a section of said duct being a barometric leg, being placed higher than the part of the liquid at atmospheric pressure.
 2. Apparatus according to claim 1, in which the supply of liquid comprises a buffer supply reservoir.
 3. Apparatus according to claim 1, in which a buffer reservoir is connected to the duct at the bottom of the barometric leg.
 4. Apparatus according to claim 3, in which the level of said reservoir is adjustable.
 5. Apparatus according to claim 1, in which the duct comprises a lengthened, wound section.
 6. Apparatus according to claim 1, in which the duct is provided with heating means.
 7. Apparatus according to claim 1, in which the duct is provided with an air eliminator.
 8. Method for creating a sub-atmospheric pressure inside closed containers, filled and/or sealed at atmospheric pressure, in which said containers are introduced into a duct full of liquid which moves from an inlet to an outlet of said duct, said liquid carrying the containers in the stream, part of said liquid being at atmospheric pressure, one section of said duct being a barometric leg, being placed higher than the part of the liquid at atmospheric pressure, the level difference between said section and said part of the liquid at atmospheric pressure being such that the containers are permanently enlarged. 